Radeon HD 6870 vs Radeon R9 M390X

Intro

Compare those specifications to the Radeon R9 M390X, which has GPU clock speed of 723 MHz, and 4096 MB of GDDR5 RAM running at 1250 MHz through a 256-bit bus. It also features 2048 Stream Processors, 128 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M390X		125 Watts
Radeon HD 6870		151 Watts
	Difference: 26 Watts (21%)

Memory Bandwidth

Theoretically speaking, the Radeon R9 M390X should perform a little bit faster than the Radeon HD 6870 overall. (explain)

Radeon R9 M390X		160000 MB/sec
Radeon HD 6870		134400 MB/sec
	Difference: 25600 (19%)

Texel Rate

The Radeon R9 M390X will be much (more or less 84%) more effective at AF than the Radeon HD 6870. (explain)

Radeon R9 M390X		92544 Mtexels/sec
Radeon HD 6870		50400 Mtexels/sec
	Difference: 42144 (84%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 6870 is a better choice, and very much so. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon R9 M390X		23136 Mpixels/sec
	Difference: 5664 (24%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of data (measured in MB per second) that can be transported over the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.